Nephrotic syndrome is a condition caused by a group of diseases that damage the kidney's filtering system, the glomeruli. The two main features of nephrotic syndrome are excess excretion of proteins in the urine (proteinuria) and lower level of protein in the blood (hypoalbuminemia). Other major symptoms include swelling (edema) and high level of cholesterol in the blood (hypercholesterolemia).
Nephrotic syndrome may be caused by both kidney diseases and non-kidney diseases, such as diabetes, lupus and hypertension. Primary causes include minimal change disease, focal segmental glomerulosclerosis, membranous glomerulonephritis, membranoproliferative glomerulonephritis and mesangial proliferative glomerulonephritis.
Nephrotic syndrome is usually diagnosed by clinical testing and confirmed by renal biopsy. An initial urinalysis is done to measure the amount of protein in the urine by collecting urine for 24 hours. A blood test is commonly done to detect the protein, cholesterol and triglyceride levels in the blood. It is common to have abnormal blood overclots (coagulopathies) due to the urinary loss of certain protein in patients with nephrotic syndrome. A blood test may also be used to detect serum levels of factor VIII, fibrinogen and platelets.
Treatment of nephrotic syndrome is directed at the underlying disease. Some of the diseases that cause nephrotic syndrome can be treated with medication. Some do not require treatment and will get better on their own. However, many of the underlying diseases causing nephrotic syndrome have no treatment. There remains a need for an effective treatment for nephrotic syndrome.